In this study, the yttrium trifluoride-doped polyacrylonitrile(PAN) based carbon nanofibers (YF₃-PAN-CNFs) are successfully designed and prepared through the electro-blow spinning and carbonization strategies. And the YF₃-PAN-CNFs acted as main materials of functional layer for modifying separator of lithium metal batteries are systematically studied and analyzed. The prepared CNFs have long-range ordered structures and high conductivity, which can extremely improve the transport of lithium ions and electrons during charge-discharge processes. The lithiophilic YF₃ nanoparticles formed in the carbonization process can endow enough active sites to produce alloying reaction with Li, which makes the plating/stripping of Li more uniform. For the assembled Li||lithium iron phosphate(LiFePO₄) battery, it still maintains a high specific discharge capacity of 137.1 mAh g^-1 after 500 cycles at 0.5 C, which there is almost no specific discharge capacity degradation after long cycle. The modified separator for the Li||Li symmetric battery can effectively suppress the growth of lithium dendrites and improve cycle stability. Meanwhile, based on the strong chemical bonding between YF₃ and lithium polysulfide combining the effectively physical confinement of the YF₃-PAN-CNFs coating layer, the “shuttle effect” of lithium polysulfide also can be greatly suppressed. Thus the assembled Li||S battery using the separator has excellent electrochemical performance. Therefore, the YF₃-PAN-CNFs modified separator will have a promising application prospect in lithium metal batteries even other high performance secondary batteries.

在这项研究中，通过电吹纺和碳化策略成功设计和制备了三氟化钇掺杂聚丙烯腈 (PAN) 基碳纳米纤维 (YF _{3 -PAN-CNFs)。}并对YF ₃ -PAN-CNFs作为锂金属电池隔膜改性功能层的主要材料进行了系统的研究和分析。制备的CNFs具有长程有序结构和高导电性，可以极大地改善充放电过程中锂离子和电子的传输。亲锂 YF ₃在碳化过程中形成的纳米粒子可以赋予足够的活性位点与锂发生合金化反应，使锂的沉积/剥离更加均匀。对于组装好的Li||磷酸铁锂(LiFePO ₄ )电池，在0.5C下循环500次后仍保持137.1 mAh g ^{-1的高比放电容量，长时间循环后几乎没有比放电容量下降。}用于Li||Li对称电池的改性隔膜可有效抑制锂枝晶的生长，提高循环稳定性。同时，基于YF ₃与多硫化锂之间的强化学键结合YF 3 的有效物理_限制-PAN-CNFs包覆层，多硫化锂的“穿梭效应”也能得到极大抑制。因此使用该隔膜组装的Li||S电池具有优异的电化学性能。因此，YF ₃ -PAN-CNFs改性隔膜在锂金属电池乃至其他高性能二次电池中具有广阔的应用前景。